CVE-2026-20033 is a vulnerability in Cisco Nx Os
Published on February 25, 2026
Cisco NX-OS Software Denial of Service Vulnerability
A vulnerability in Cisco Nexus 9000 Series Fabric Switches in ACI mode could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to insufficient validation when processing specific Ethernet frames. An attacker could exploit this vulnerability by sending a crafted Ethernet frame to the management interface of an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition.
Note: Only the out-of-band (OOB) management interface is affected.
Vulnerability Analysis
Weakness Type
Buffer Access with Incorrect Length Value
The software uses a sequential operation to read or write a buffer, but it uses an incorrect length value that causes it to access memory that is outside of the bounds of the buffer. When the length value exceeds the size of the destination, a buffer overflow could occur.
Products Associated with CVE-2026-20033
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Affected Versions
Cisco NX-OS System Software in ACI Mode:- Version 15.2(1g) is affected.
- Version 15.2(2e) is affected.
- Version 15.2(2f) is affected.
- Version 15.2(2g) is affected.
- Version 15.2(2h) is affected.
- Version 15.2(3f) is affected.
- Version 15.2(3e) is affected.
- Version 15.2(3g) is affected.
- Version 15.2(4d) is affected.
- Version 15.2(4e) is affected.
- Version 15.2(5c) is affected.
- Version 15.2(5d) is affected.
- Version 16.0(1g) is affected.
- Version 15.2(5e) is affected.
- Version 15.2(4f) is affected.
- Version 15.2(6e) is affected.
- Version 15.2(6h) is affected.
- Version 16.0(1j) is affected.
- Version 15.2(6g) is affected.
- Version 15.2(7f) is affected.
- Version 15.2(7g) is affected.
- Version 16.0(2h) is affected.
- Version 15.2(8d) is affected.
- Version 16.0(2j) is affected.
- Version 15.2(8e) is affected.
- Version 16.0(3d) is affected.
- Version 16.0(3e) is affected.
- Version 15.2(8f) is affected.
- Version 15.2(8g) is affected.
- Version 15.3(1d) is affected.
- Version 15.2(8h) is affected.
- Version 16.0(4c) is affected.
- Version 15.3(2a) is affected.
- Version 15.2(8i) is affected.
- Version 16.0(5h) is affected.
- Version 15.3(2b) is affected.
- Version 16.0(3g) is affected.
- Version 16.0(5j) is affected.
- Version 15.3(2c) is affected.
- Version 16.0(6c) is affected.
- Version 15.3(2d) is affected.
- Version 16.1(1f) is affected.
- Version 16.0(7e) is affected.
- Version 16.0(8e) is affected.
- Version 15.3(2e) is affected.
- Version 16.0(8f) is affected.
- Version 16.1(2f) is affected.
- Version 16.1(2g) is affected.
- Version 15.3(2f) is affected.
- Version 16.0(9c) is affected.
- Version 16.1(3f) is affected.
- Version 16.0(9d) is affected.
- Version 16.0(6h) is affected.
- Version 16.0(8h) is affected.
- Version 16.1(3g) is affected.
- Version 16.0(9e) is affected.
- Version 16.1(4h) is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.